Dry powder inhalation (DPI) devices are generally used for inhalation of powdered medicament from capsules. The DPI devices may either single dose or multidose. In the single dose or multiple unit dose DPI formulations, the drug is pre-packaged in capsules or blisters. The reservoir DPI formulations involve a device containing at least a reservoir and a metering chamber to administer an accurate dose of the drug.
Medicament holders, particularly for inhalation devices known in the art are used for receiving and holding a medicament in granular form or powder form, or volatile form or in a capsule containing powdered or volatile medicament. The configuration of the holder is such that the medicament or the capsule located inside the chamber is rotated or moved up and down by air flowing through the chamber in order to disperse the powdered drug medicament into air being sucked.
The medicament holders, for example capsule chambers, known in the art are generally tubular or cylindrical in shape with an air inlet and air outlet arranged coaxially at the bottom and top ends respectively. The air inlet is generally smaller and outlet opening generally larger than the diameter of the capsule. A mouthpiece is arranged axially to the air outlet. Generally, a piercing mechanism is provided to pierce the capsule to enable the medicament present in the capsule to be inhaled. During inhalation, air passes from the air inlet and causes movement of the capsule, and due to this, the medicament present in the capsule is carried by the air to the air outlet opening and mouthpiece and reaches the patient's lungs.
Single dose DPI devices working with capsules, usually possess a system to pierce the capsule. After piercing, the patient inhales the powder contained in the capsule through the device without swallowing the capsule. The capsule remains in the device which is discarded from the device prior to the next use of the device.
WO 91/06333 describes a device for dispensing single doses of a powdered medicament from a container having a plurality of apertures, each of which holds a respective one of said doses, and is sealed by two opposed seals. The device comprises a housing for holding the container, the housing having an outlet and an airway, which communicates with the outlet and being configured to allow the container to move relative thereto to bring each aperture in succession into registry with the airway. The device includes a piercing member movable from a retracted position in which it is positioned clear from the container into an extended position in which it extends into the aperture, said movement causing rupture of the seals, while expelling substantially no medicament from the aperture.
U.S. Pat. No. 5,685,294 discloses an inhaler for inhalation of powdered medicament, more particularly a microionised drug preparation, from capsules, the housing of the inhaler comprising tubular chambers for receiving and holding medicament-containing capsules in a revolver magazine with an air inlet at the bottom and an air outlet at the opposite end of the chamber opening into a mouth piece, a cutting device with two blades which are movable into the interior of the chamber in order to open the capsules near the top and bottom ends thereof.
U.S. Pat. No. 3,807,400 discloses an inhaler comprising an upper member comprising a whirling chamber; a lower member comprising a capsule-receiving chamber and a series of cams and recesses on the inner wall of the lower member; and piercing members resiliently biased away from a capsule received in the capsule-receiving chamber by the action of a spring. In use, rotation of upper and lower members relative to each other causes reciprocations of the piercing members against the cams and recesses provided on the inner wall of the lower member, so as to effect a number of diametrically opposed piercing operations on the capsule.
U.S. Pat. No. 3,795,244 discloses an inhaler comprising a housing; a rotary member located within the housing and having at one end engagement means adapted to receive a medicament-containing capsule; and a piercing assembly comprising opposed arms with piercing pins mounted thereon and a tubular member slidable relative to the housing and having cam projections from the inner wall. In use, and prior to inhalation, the user inserts a capsule into the engagement means and is then required to manually slide the tubular member towards the mouthpiece, so that the cams provided on the inner wall of the tubular member push opposed piercing arms towards the capsule, resulting in perforation of the capsule at its free end. The user is then required to manually return the tubular member to its original position, allowing the piercing arms to return to the non-piercing position.
U.S. Pat. No. 4,069,819 discloses a dry powder inhaler device comprising a nebulising chamber adapted to receive a medicament-containing capsule. A capsule received in the chamber is freely moveable within it. In use, air flow through the nebulising chamber and around the capsule contained therein causes the entire capsule to move within the nebulisation chamber.
U.S. Pat. No. 3,635,219 discloses a dry powder inhaler device comprising a propeller-like member rotatably mounted in a housing and having mounting means adapted to receive a medicament-containing capsule. In use, flow of inhaled air through the device causes rotation and vibration of the propeller-like member and a capsule mounted thereon, so dispensing medicament into the air stream. The device further comprises spring-loaded piercing members mounted in the housing so as to be normally urged into an inoperative position but which may be manually pushed inwards to perforate a medicament containing-capsule received in the device by the action of pushbuttons or sliding cams.
U.S. Pat. No. 3,906,950 describes a dry powder inhalation device comprising a swirl compartment and, separately, a capsule-receiving cavity comprising two components, said cavity slidably attached to a pair of relatively moveable elements which hold piercing needles and which telescopically slide inside capsule holder components against the action of a pair of return springs.
U.S. Pat. No. 5,947,118 relates to a capsule holder for receiving two part capsules, which holder comprises a recess adapted to receive a capsule, wherein the sidewalls of the recess have three or more ribs arranged parallel to the central axis of the recess between which capsules can be clamped by both upper and lower parts with some deformation of the capsule walls. The relative dimensions of the cylinder defined by the ribs and the capsule is such that in use, a capsule received by the ribs is clamped and held firmly in place within the holder.
U.S. Pat. No. 4,889,114 discloses a dry powder inhaler device comprising a capsule-receiving chamber comprising an air inlet and an air outlet located at opposed ends of the chamber. In use, air flow through the chamber on inhalation causes movement of a capsule received therein, between the air inlet end and the air outlet end of the capsule-receiving chamber. The capsule is freely moveable within the confines of the chamber.
All the known inhalation devices require the user of the device to open the device, insert a medicament-containing capsule, close the device, and pierce the capsule manually by a pushing or rotating action prior to inhalation of the medicament. The user has to perform numerous actions before actual inhalation of the medicament.
We have found that the known medicament holders also have the disadvantage of requiring the user of the inhaler to inhale very deeply in order to try to inhale the full dose of the medicament.
Having appreciated these drawbacks, we have now devised an improved inhaler device and holder.